Equine induced pluripotent stem cells are responsive to inflammatory cytokines before and after differentiation into musculoskeletal cell types

Abstract

Persistent inflammation is associated with the poor regeneration of musculoskeletal tissues. Embryonic stem cells (ESCs) have an attenuated response to inflammatory cytokines, but there are mixed reports on the response of induced pluripotent stem cells (iPSCs) to inflammation. Horses provide a relevant large animal model for studying musculoskeletal tissue diseases and the testing of novel therapies. The aim of this study was to determine if equine iPSCs are responsive to the inflammatory cytokines IL-1β, TNFα and IFN-γ in their undifferentiated state, or following differentiation into tendon and cartilage-like cells. We demonstrated that in undifferentiated iPSCs, the cytokines induce NF-κB P65 and STAT1 nuclear translocation which leads to cell death, decreased OCT4 expression and increased expression of inflammatory genes. Following differentiation towards cartilage-like cells exposure to the cytokines resulted in STAT1 nuclear translocation, changes in cartilage gene expression and increased expression of matrix metalloproteinases (MMPs) and inflammatory genes. Exposure of iPSC-derived tendon-like cells to the cytokines resulted nuclear translocation of NF-κB P65 and STAT1, altered tendon gene expression, increased MMP expression and increased expression of inflammatory genes. Equine iPSCs are therefore capable of responding to inflammatory stimulation and this may have relevance for their future clinical application.

A Functional Single-Nucleotide Polymorphism Upstream of the Collagen Type III Gene Is Associated with Catastrophic Fracture Risk in Thoroughbred Horses

“…We therefore examined the cellular localisation of STAT1 and RUNX2 in either the cells derived from high- and low-risk horses, but no significant differences were observed ( Figure 5 ). Although STAT1 is ubiquitously expressed in both pre- and postosteogenic differentiation, we have previously demonstrated the specificity of the STAT1 antibody to the equine protein [ 57 , 58 ].…”

“…We therefore examined the cellular localisation of STAT1 and RUNX2 in either the cells derived from high-and low-risk horses, but no significant differences were observed (Figure 5). Although STAT1 is ubiquitously expressed in both preand postosteogenic differentiation, we have previously demonstrated the specificity of the STAT1 antibody to the equine protein [57,58]. To identify novel SNPs that may be responsible for the differential expression of STAT1 and COL3A1, we carried out preliminary whole-genome sequencing on two fracture cases and two controls.…”